Abrading tool



March 23, 1943. J. c. GARAN D ABRADING TOOL Filed Jan. 23, 1942ZAShe'ets-Sheet 1 a] John llllafand March 23, 1943. J, c, GARANDABRADING TOOL Filed Jan. 23, 1942 2 Sheets-Sheet 2 gnuw m :lmhn ll Barand j/W time/ 4 sa /21W Patented Mar. 23, 1943 UNITEDSTATES PATENTOFFICE ABRADING TOOL John C. Garand, Springfield, Mass. ApplicationJanuary 23, 1942, Serial No. 427,929

(Cl. 51-1841) (Granted under the act of March 3, 1883, as

6 Claims.

amended member of an abrading machine tool in engage ment with the work.Another object is to provide an abrading tool whereby the abrasivemember is held in engagement with the work by either spring or fluidforces or by a combination of both forces.

Another object of my invention is to provide an abrading tool wherebythe abrasive is held in engagement with the work by spring force, whichforce is supplemented by a fluid pressure force, which fluid is thenutilized for efficient and effective lubrication of the abradingsurfaces.

A further object of my invention is to provide a power-driven abradingtool particularly adapted for abrading interior surfaces. A deviceembodying my invention will further permit the effective abraoling ofinterior cylindrical surfaces by either a longitudinal motion of theabrasive member, or by a rotary motion, or by any combination oflongitudinal and rotary motion.

A particular object of my invention is to provide an abrasive supportingfixture adapted to be driven by power mechanism for abrading theinterior cylindrical surface of the chamber of a firearm, whereby theabrasive member is held in work engaging position through the combinedforces of a spring and a fluid pressure, which fluid is also utilized tolubricate the work and abrading surfaces. In performing abradingoperations, or more particularly, honing operations, upon the interiorsurface of the chamber of the firearm, it is essential that theabrasions produced on such surface are longitudinal to permit the readyextraction of a cartridge from such chamber after firing of thecartridge. A device embodying the features of my invention permits sucha longitudinal honing operation to be readily accomplished.

ihe specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

, Fig. 1 is an external view of an assembled April 30, 1928; 370 O. G.757) abrading fixture constructed in accordance with my invention;

Fig. 2 is a longitudinal sectional view of theassembly in Fig. 1 takenon the line 2-4;

Fig. 3 is a cross-sectional on the line 33;

Fig. 4 is a cross-sectional view of Fig. 2 taken on the line 4-4;

Fig. 5 is a perspective view of the abrasive member assembled to theholding member;

Fig. 6 is a perspective view of the fluid guide;

Fig. 7 is a broken view in longitudinal section of the forward portionof the abrading fixture in position for use in a barrel chamber; and

Fig. 8 is a cross-sectional view of the assembly in Fig. '7 taken on theline 8'-8.

Referring to the drawings wherein like numerals in each view refer tosimilar parts, one embodiment of my improved abrading tool comprises along, generally cylindrical, abrasive supporting member I having at oneend thereof a portion 2 of slightly reduced diameter and a shank 2a forengagement by the tool engaging member of a driving apparatus. Thedriving apparatus for the abrasive supporting member I has not beenshown but it should be understood that it may be of any conventionaltype which will engage the abrasive supporting member I and, drive itwith any desired longitudinal or rotary motion or combination thereof.On the other end of the abrasive supporting member I there is provided areduced diameter extension 3 having a tapered nose which performs afunction to be explained later. The abrasive supporting member I isprovided in its central portion with one or more longitudinal slots 4which extend into extension 3. Each of these slots will support anabrasive member in a manner to be explained and, hence, it is apparentthat any desired number of such slots may be provided depending onlyupon the desired diameter of supporting member I and the width of theabrasive members which it may be desired to use. In my preferredembodiment I provide two such slots 4 which are diametrically oppositeand are best shown in cross-section in Figs. 3 and 4. Each slot 4 is ofappreciable depth with respect to the radius of supporting member I anddefines side walls 5 and base 6. Hereinafter the description willproceed with respect to only one of such slots 4 but it should beunderstood that the other slot 4 and its cooperating members will beidentical to the structure described. v

The supporting member I is longitudinally drilled through its end 2 toprovide a fluid supply view of Fig. 2 taken I passage 1 whichcommunicates between a source of fluid within the driving apparatus (notshown) and the end of slot 4 by way of the small fluid entrance chamber9. The entrance chamber 9 is conveniently formed by drilling through thebase 6 of slot 4. The slot 4 is preferably provided with a semi-circularend portion I2 substantially tangent to the entrance chamber 9. Theother end wall of slots 4 isgiven a rectangular shape by means ofinserts 3a which fill the slotted portions of extension 3 and aresecured therein bymeans of the pin 3b.

Adjacent to the center portions of slot 4-there is provided on each sidewall 5, a lip Iiloverhanging the slot 4. Likewise at the end of slot 4,adjacent to the reduced diameter portion 3,

overhanging lips II are provided (Fig. 4)

A fluid guide I3 (Fig. 6) is provided of suitable shape and dimension topermit it to fit in the slot 4. One end I5 of the fluid guide I3 issemicircular to engage the correspondingly shaped end I2 of slot 4. Theother end of fluid. guide l3 is provided with'recessedportions- I6 whichare adapted to engage the undersurface of center lips II] when fluidguide I3- is inserted in slot 4. The exterior surface of fluid guide I3is preferably'of the same arcuate shape as thesu-pporting member I sothat when fluid guide I3 is inserted in slot 4 the resulting assemblageis of substantially cylindrical cross-sectionas best shown in Figure 3.The interior su-rface'of fluid guide I3 is provided with a longitudinalslot I4 which serves as afluid passage. This fluid passage I4 at oneendoverliesthe-fluid chamber 9 and at its otherend overlies a fluiddispersion chamber 8 which is formed by' cutting a slot through the base6 of slot 4 in that portion adjacentthe center lips ID.

The abrasive member I8 is of a longitudinal rectangular shape havingonearcuate surface I8a ofsubstantially the-same radius as the surface ofsupporting member I (Fig. 4). The abrasive I8- is engaged throughout itslength by a metallic holding member I9 which is generally U shape incross-section and its exterior dimensions are such as to readily fit inthe slot 4. The length of the arms ofthe U-is less thanthe clearancebetween the lips H3 or IIandthe base 6 of'slot 4. The widthof theabrasive member l 3 permits its passage between the lips ID or II. The Ushaped holding member I9 is cemented or otherwise fastenedaround-thenon-arcuate sides-of the abrasive I8. Thus when the assemblageof holder I9 and abrasive I8is placed in slot 4 the arcuate surface ofabrasive I8 will form a segment of a cylinder substantially coaxial withand of slightly larger diameter than the supporting member I. At eachend of the holder I9 cut-away portions 23 are providedwhichengagewithlips I0 and Ii upon assemblage of the holder I9 within that portionofslot 4 between lips I9 and II and allow for limited radial movement ofthe holder and abrasive. An-arcuate leaf spring 2| is provided forinsertion between the holder I9 and the base 6 of slot 4; The end ofspring 2| underlying center lip Ii] is engaged by a recess 24 providedon the abutting. end'of fluid guide I3.

In assembling. the Various elements in slot 4 the spring 2| is firstinserted in the left hand. portion of slot 4 and then slid into theright hand portion of slot 4 andheld therein by the lips I6 and II-. Theholder H] with the abrasive I8 is inserted in a similar manner in theleft hand portion of slot 4 and is slid longitudinally of the slot intothe right hand portion of the slot on top of spring 2|. The holder I9 isthus forced outwardly by spring 2| so that its cut away portions 20yieldingly engage the lips I0 and I I. Then the fluid guide I3 isdropped into place and, as previously pointed out, the recess 24 engagesthe end of spring 2| limiting longitudinal movement thereof. At the sametime the end of fluid guide I3 abuts against the end of holder I9,preventing longitudinal movement of the holder I9 and hence, of theabrasive I8.

The fluid guide I3 is held securely in place by set screws 23 mounted ina collar 22 which surrounds supporting member I. The collar 22 isprovided with an interior ridge 25 which engages the shoulder 2b formedby the transition of diameter between portion 2 and the main portion ofsupporting member I. Since the set screw 23 engages the depression I!(Fig. 2) in fluid guide member I3, the fluid guide member I3 is securelylocked against any type of movement, and hence the abrasive member I8cannot be disengaged from the supporting member I. It will be apparentfrom the foregoing description that the tool may be quickly disassembledand a worn abrasive member replaced.

In operation, the assemblage carrying the abrasive members I8 isinserted within the interior surface of the work piece. The spring 2Ioperates-to force the abrasive member outward into engagement with thework surface. The force of the spring is supplemented by fluid pressurewhich fluid is supplied through passage 1, entrance chamber 9.longitudinal slots I4 and dispersion chamber 8. After entering chamber8-the fluid fills the space between base 6 of slot 4, and the base ofholder I9, exerting an additonal outward force pressing the abrasive I8into engagement with the work surface. The provision of the chamber 8insures equalization of the fluid pressures applied to each of theabrading members. This additional fluid force is of course adaptable toregulation through a substantial range by variation of the pressure atwhich the fluid is supplied. At the same time the fluid is forcedthrough the clearances between the sides of holder I9 and the sides 5 ofslot 4 and is thus supplied to lubricate the working surface of abrasiveI8 and the work surface. It is apparent that such an abrading tool maybe readily operated with a rotary or longitudinal motion or anycombination thereof.

The reduced diameter extension 3 of supporting member I performs animportant function when a device embodying my invention is utilized inthe longitudinal honing of the interior surface of the chamber of afirearm as shown in Fig. 7 It has been found convenient to perform suchhoning operations with the barrel 21 of the firearm in a verticalposition with the chamber 28 at the bottom. If the extension member 3 isnot provided, it is found that the close coaction of the surfaces of thetool and the chamber surface would produce a piston-like effect upon thelubricating fluid. A pumping action would result and the lubricatingfluid would gradually be pumped up through the barrel. The provision ofthe extension 3 on supporting member I prevents such pumping action byentering the reduced diameter portion 28a of the chamber 28 on eachupstroke of the abrasive supporting member I. The diameter of extension3 is such as to produce only a small clearance between it and walls ofchamber portion 28a as shown in Fig. 8. Hence in effect a sealing actionis produced between extension 3 and chamber portion 2&1 preventing asubstantial amount of fluid from being pumped upward into the barrel.The fluid of course is drained from the chamber by gravity and iscollected for recirculation by conventional means.

The construction disclosed has the further advantage that, if desired,the abrading tool may be operated without the use of the lubricatingfluid, using only a suitable spring 2| to force the abrasive member l8against the working surface. Conversely the spring 2| may be omitted andthe operating force produced entirely by the pressure of the lubricatingfluid.

I claim:

1. A tool for abrading interior surfaces comprising in combination, asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide membersinserted in part of each of said slots and detachably secured therein,abrading elements inserted in the remaining part of each of the slotsand secured therein by the abutting fluid guide member, resilient meansforcing the abrading element into work engaging relation with the work,a fluid passage connecting that base portion of each slot underlying theabrasive elements with the fluid guide member and means for supplyinglubricating fluid to the fluid guide member.

2. A tool for abrading interior surfaces comprising in combination asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide membersinserted in part of each of said slots and detachably secured therein,abrading elements inserted in the remaining part of each of the slotsand secured therein by the abutting fluid guide member, resilient meansmounted between each of said abrading elements and the underlying baseof its slot forcing the abrading element 'into engaging relation withthe work, a'fluid'dispersion chamber connecting the underlying-, baseportion of each slot with the fluid guide members, means for supplyinglubricating fluid under pressure to the fluid guide members, said fluidpressure producing a Work engaging force on the abrading elements, andleakage means whereby said fluid lubricates the working surfaces of theabrading elements.

3. A tool for abrading interior surfaces comprising in combination, asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide membersinserted in part of each of said slots and detachably secured therein,abrading elements inserted in the remaining part of each of the slotsand secured therein by the abutting fluid guide member, a fluid passageconnecting that base portion of each slot underlying the abrasiveelements with the fluid guide member and means for supplying lubricatingfluid to the fluid guide member.

4'. A tool for abrading interior surfaces comprising in combination asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide membersinserted in part of each of said slots and detachably secured therein,abrading elements inserted in the remaining part of each of the slotsand secured therein by the abutting fluid guide member, a fluiddispersion chamber connecting the underlying base portion oi each slotwith the fluid guide members, means for supplying lubricating fluidunder pressure to the fluid guide members, said fluid pressure producinga work engaging force on the abradin elements, and leakage means wherebysaid fluid lubricates the working surfaces of the abrading elements.

5. A tool for abrading interior surfaces comprising in combination, asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide members inpart of each of said slots, abrading elements in the remaining part ofeach of the slots, overhanging portions of said slot retaining theabrading elements in the slot at their ends and further overhangingportions of the slots retaining the other ends of the abrading elementsand the adjacent ends of the fluid guide members in the slots, andremovable means for holding the other ends of the fluid guide members inthe slots.

6. A tool for abrading interior surfaces comprising in combination asupporting member adapted to be inserted in the work to be treated,longitudinal slots in said supporting member, fluid guide members inpart of each of said slots, abrading elements in the remaining part ofeach of the slots, overhanging portions of said slot retaining theabrading elements in the slot at their ends and further overhangingportions of the slots retaining the other ends of the abrading elementsand the adjacent ends of the fluid guide members in the slots, andremovable means for holding the other ends of the fluid guide members inthe slots, a fluid passage connecting that base portion of each slotunderlying the abrasive elements with the fluid guide member and meansfor supplying lubricating fluid to the fluid guide member.

JOHN C. GARAND.

